There is shown in FIG. 1 a conventional electromagnetic wave detecting device 1 including a half-wave dipole antenna 3 and a rectifying diode 5. In the electromagnetic wave detecting device, an electromagnetic wave is detected by the rectifying diode 5 converting a radio frequency signal to an electrical signal when the half-wave dipole antenna 3 receives an electromagnetic wave.
In such an electromagnetic wave detecting device, it is difficult to manufacture a nonlinear element such as a diode capable of operating in a frequency range greater than the millimeter wave frequency regime (30-300 GHz).
There is shown in FIG. 2 another conventional electromagnetic wave detecting device 2 for use in a frequency range greater than millimeter waves.
As shown, the electromagnetic wave detecting device 2 includes a half-wave dipole antenna having a pair of arms 12a, 12b for receiving an electromagnetic wave power, a heating element or a heater 13 disposed between the arms 12a, 12b of the dipole antenna, for converting the radiant energy received by the arms 12a, 12b to the thermal energy, a thermal sensor 15 for sensing the temperature changes of the heater 13, a pair of terminals 17 for measuring the changes in resistance of the thermal sensor 15, and a pair of signal lines 16 for coupling the thermal sensor 15 and the terminals 17.
The thermal sensor 15 is conventionally made of a temperature sensitive material, such as vanadium oxide(VO.sub.2), having a large TCR (temperature coefficient of resistance).
However, such a temperature sensitive material, e.g., VO.sub.2, requires a heat treatment at higher than, e.g., 500.degree. C., which is not compatible with a CMOS (complementary metal-oxide-semiconductor) process used in forming driving circuitry (not shown) of the electromagnetic wave detecting device. As a result, the detecting device and the driving circuitry may not be fabricated simultaneously in a process, requiring additional fabrication process.